GE 90-70 manual Debugger, Stop to RUN Mode Transition, Background Window Time

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a scan set that is scanned every other sweep (that is, PERIOD=2), then the Primary CPU might scan its scan set in one sweep and the Secondary CPU scan its scan set in the next.

Use of non-default scan sets can cause variance in the time the units get to the rendezvous points. This should be considered when determining the failwait time.

C Debugger

The Embedded C debugger may be used for debugging Standalone C programs and EXE blocks. Use of the embedded C debugger in a Redundancy CPU is limited to when the system is not synchronized. The CPU will reject any attempt to establish a debugger session while the units are synchronized. If the debugger is active on one unit while the two units are not synchronized, then any attempt to synchronize the two units will fail. Specifically, if the unit in RUN mode has a debugger session active and the other unit is commanded to go to RUN mode, the unit commanded to go to RUN will log a fault and go to STOP/FAULT mode.

STOP to RUN Mode Transition

A resynchronization will occur at all STOP to RUN mode transitions. The time to perform this resynchronization may be larger than STOP to RUN transitions on non-redundancy CPUs. The STOP to RUN mode transition has two separate paths.

1.If the CPU performing the transition is doing so alone or both CPUs are transitioning at the same time, then a normal STOP to RUN mode transition is performed (clear non-retentive memory and initialize FST_SCN and FST_EXE).

2.If the other CPU is active when this CPU performs a STOP to RUN mode transition, then non- retentive references will be cleared followed by a resynchronization with the active CPU.

Background Window Time

In a redundancy system, this value may be set to zero. Unlike other CPU models which have a default of 0mS, the default value for the Redundancy CPU is 5ms.

Setting the background window time to zero disables the verification of the Series 90-70 CPU operating system software and the CPU self-tests.

Sequential Function Chart Programming (SFC)

SFC Program Blocks can be used in the program logic. However, the redundant CPU system will not attempt to coordinate and synchronize the execution of the SFC charts between the two CPUs. For example, if one of the units is in Run mode at the time the other is placed in Run mode, the running unit will typically be in the middle of its chart, and the transitioning unit will typically be at the beginning of its chart. As a result, the SFC state and paths taken by the two CPUs will be different and the backup unit will not be able to take over exactly where the active unit left off.

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Series 90™-70 Enhanced Hot Standby CPU Redundancy User's Guide – May 2000

GFK-1527A

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Contents GE Fanuc Automation GFL-002 Preface Content of This ManualRelated Publications Preface Contents Contents Chapter Fault Detection Appendix a Cabling Information Definition of Terms IntroductionEnhanced Hot Standby CPU Redundancy Compatibility with CPU780 Using the Redundancy CPU for Non-Redundant OperationRedundancy CPUs as Compared to Other Series 90-70 CPUs Features not Available with Redundancy CPUsDifferences in Operation for Redundancy CPUs Redundancy Communications Module Enhanced Redundancy CPU ModuleRedundant Racks Systems for Enhanced Hot Standby CPU RedundancyLocal I/O Genius I/OCable Connections Local I/0 Can be Enhanced Hot Standby CPU Redundancy System with Local I/OGHS Control Strategy Control StrategiesGDB Control Strategy Output Control with GHS Basic Enhanced Hot Standby OperationOutput Control with GDB Single Bus with Preferred Master GHS Control Strategy Basic CPU Redundancy SetupsCritical Data + Redundant Outputs Transferred Single Bus with Floating Master GDB Control StrategyPaired GBC = INT/EXT Internal External Dual Bus with Floating Master GDB Control StrategyOn-Line Repair Online ProgrammingDuplex CPU Redundancy System Components For Installation InstructionsSystem Racks Redundancy CPU FeaturesCPU Architecture Watchdog TimerExpansion Memory Board Memory Protect Keyswitch CPU FeaturesBattery Connectors CPU LEDsPort CPU Mode SwitchUnit Select Pushbutton Redundancy Communications ModuleRCM Status Leds ConnectorBus Transmitter Module ConnectorsBus Transmitter Module Status LEDs Cables and Termination Bus Receiver ModuleBus Receiver Module Status LEDs Location of GBCs and Blocks Genius Bus ControllerDual Bus Genius Networks Single Bus Genius NetworksBus Controller LEDs Programmer Connection for Configuration Configuration RequirementsOne Application Program in Both PLCs Program Folders in Control Programming SoftwareProgram Folders in Logicmaster CPU Configuration ParametersParameter Default Range Description Configuring Shared I/O ReferencesSystem Communications Window Considerations Finding the Memory Available for Application Program StorageBus Controller Configuration Parameters Rack Module Configuration ParametersGenius I/O Block Configuration Parameters Normal Operation Powerup of a Redundant CPU Resynchronization of a Redundant CPU Incompatible ConfigurationsGDB Control Strategy GHS Control StrategyOvrpre %S Reference Not Available References for CPU RedundancySweep Time Synchronization Scan SynchronizationAT a Output Data Transfer to the Backup UnitFail Wait Time Data Transfer TimeGFK-1527A Normal Operation Data Transfer Example Programming a Data Transfer from Backup Unit to Active UnitDisabling Data Transfer Copy in Backup Unit Svcreq #43 Command Block for Svcreq #43 Validating the Backup PLCs Input Scan Backup Qualification with Svcreq #43Validating the Backup PLCs Logic Solution Switching Times Switching Control to the Backup UnitRUN Disabled Mode for GHS Control Strategy RUN Disabled ModeExample 1 Role switches allowed on both units Example 3 Role switches not allowed on either unit Example 2 Role switches allowed on both unitsExample 4 Role switches allowed on both units Backup Active Example 8 Invalid RUN Disabled Mode for GDB Control StrategyCGR772 CGR935 Finding the Words to Checksum Each SweepFinding the Total Sweep Time Finding the Background Window TimeMiscellaneous Operation Information Timer and PID Function BlocksTimed Contacts Multiple I/O Scan SetsSequential Function Chart Programming SFC Stop to RUN Mode TransitionDebugger Background Window TimeGenius Bus Controller Switching Ethernet Global Data Consumption Ethernet Global Data in a Redundancy CPUSntp Timestamping Ethernet Global Data ProductionConfiguration of Fault Actions Fault DetectionFault Detection Message Fault Description Corrective Action PLC Fault Table Messages for RedundancyWith redundancy in other fault groups Fault Response Losing a Link Faulting the Redundancy Communications ModuleFault Actions in a CPU Redundancy System Fault Group Type Description Configurable FaultsFatal Faults on Both Units in the Same Sweep Non-Configurable Fault GroupOn-Line Repair Maintaining Parallel Bus Termination Power SupplyOn-Line Repair Recommendations RacksRedundancy Communications Module and Cables Central Processor UnitRedundancy Communications Link Failures Bus Transmitter Module Single Bus Networks Bus faultsGenius Bus Controller Genius BusGenius Blocks Dual Bus NetworksCabling Information SpecificationsIC690CBL714A Multi-drop Cable PurposeConnector a Connector A, 15-pin Female Index Battery connectors Bus Controller, GeniusIndex Online programming Online repair Svcreq
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